The retailers banned the flags following last week's shooting in Charleston, South Carolina, in which 21-year-old Dylann Roof allegedly killed nine people in the historically black Emanuel African Methodist Episcopal Church.

Roof reportedly harbored racist sentiments and wanted to incite a "race war." He appeared to pose with the Confederate battle flag in several photos that were unearthed after the attack.

The image below shows Amazon's biggest gainers in sales rank over the past 24 hours. Five of the top six items are Confederate flags.

The shooting has led to a national debate over the appropriateness of displaying the Confederate emblem, which was a symbol of the slave-holding South during the Civil War.

South Carolina Governor Nikki Haley (R) and a bipartisan group of local elected officials announced Monday that they support removing the Confederate flag from the state capitol grounds.

The debate has since shifted to other Southern states with Confederate imagery on their banners. Mississippi prominently features the Confederate battle flag in its official state flag and some top Democrats and Republicans have said they want that changed as well.